<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
					.bk{
						/* height: 300px; */
						width: 300px;
						border: 2px solid #006400;
						position: relative; 
					}
					.diyi{
						border: 1px solid;
						background-color:red;
						
					}
					.dier{
						border: 1px solid;
						background-color: burlywood;
						position:absolute ;
						/* top: 100px;
						left: 100px; */
						/* right: 100px; */
						/* bottom: 100px; */
					}
					.disan{
						border: 1px solid;
						background-color: #00BFFF;
					position: relative;
					z-index: 6;
					
					}
				</style>
			</head>
			<body>
				<div class="bk">
					<div class="diyi">第一个盒子</div>
					<div class="dier">第二个盒子</div>
					<div class="disan">第三个盒子</div>
				</div>
			</body>
</html>
